This invention relates in general to dispensers for dispensing materials under pressure, and in particular, relates to such a dispenser which relies upon a mechanical means for the pressure source.
The use of some chemical propellants in aerosol dispensers has come under increasing criticism in recent years, and in fact, the potential damage to the environment caused by the propellants used in aerosol dispensers has resulted in legislation being passed in many areas preventing or prohibiting the use of such propellants in dispensing devices after a specified date. Of course, potential harm to the environment, and specifically the ozone layer in the atmosphere, is only one of the disadvantages of propellants used in dispensing devices. Other disadvantages relate to the dangerous nature of the pressurized containers, which must be handled carefully and not stored at elevated temperatures or punctured or incinerated by the user, since an explosion may result.
The present invention uniquely solves the problems presented by prior art aerosol devices, in that it does not rely upon the use of pressurized gases which may be harmful to the environment and does not store material under pressure, such that an explosion could occur under certain conditions. In the present invention, a pressurization chamber or reservoir has a piston reciprocable therein and means extends into the reservoir into operative association with the piston for moving the piston in a first direction to draw material from a container into the reservoir. Movement of the piston in the first direction compresses a spring or other compressible or yieldable means, such that the piston is urged in a return or second direction under pressure against the material drawn into the reservoir, and subsequent operation of a valve or spray nozzle enables escape of the material pressurized by the piston to obtain a fine spray mist for a prolonged period of time. The reservoir and operating means associated therewith can be easily attached to and removed from a container of conventional construction, if desired, whereby the container may be refilled with a material to be dispensed. Moreover, the unique pressure dispenser of the invention operates for a longer period of time and obtains a finer mist than prior art devices of the pump type or squeeze type, which only dispense in short bursts, as determined by the amount of time it takes the finger to push the plunger down, and which also produce uneven sprays of the material being dispensed.
Other prior art devices utilize various constructions to obtain prolonged discharge time or increased pressure by the use of hydraulic or pneumatic pressure advantages. However, such prior art devices are relatively complex and expensive in construction and manufacture, or are difficult and clumsy to operate.
With the present invention, the dispenser is economical to manufacture because of the simplicity in construction thereof, and the problem of user fatigue is eliminated due to the simple manner in which the device is operated. In other words, a plunger is pulled once to charge the reservoir with an amount of material, and the discharge or spray nozzle is then easily operated with the finger to obtain a prolonged, high pressure discharge or spray of the material.
Additionally, many prior art devices can only be used with a specially designed container, and some such devices are not refillable. With the present invention, the reservoir and dispensing means can be used with many conventional containers of glass, plastic or metal and the like, and the containers are easily refillable.